modpost: fix inverted logic in is_extable_fault_address().

As Guenter pointed out, we want to assert that extable_entry_size has been
discovered and not the other way around.  Moreover, this sanity check is
only valid when we're not dealing with the first relocation in __ex_table,
since we have not discovered the extable entry size at that point.

This was leading to a divide-by-zero on some architectures and make the
build fail.

Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
CC: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Quentin Casasnovas 2015-04-16 13:03:32 +09:30 committed by Rusty Russell
parent 6c730bfc89
commit d3df4de7eb

View File

@ -1529,7 +1529,12 @@ static void find_extable_entry_size(const char* const sec, const Elf_Rela* r,
}
static inline bool is_extable_fault_address(Elf_Rela *r)
{
if (!extable_entry_size == 0)
/*
* extable_entry_size is only discovered after we've handled the
* _second_ relocation in __ex_table, so only abort when we're not
* handling the first reloc and extable_entry_size is zero.
*/
if (r->r_offset && extable_entry_size == 0)
fatal("extable_entry size hasn't been discovered!\n");
return ((r->r_offset == 0) ||